Disk drive having a reinforcing arrangement against an external stress applied thereto

ABSTRACT

In a disk drive for using a disk cartridge including a magnetic disk, a reinforcing arrangement is coupled to a main frame, a main board, and a disk receiving/ejecting mechanism which is for receiving and ejecting the disk cartridge. The reinforcing arrangement resists an external stress applied between the main frame and a cover opposite to the main frame to protect a head assembly which is movable between the main frame and the cover in a radial direction of the magnetic disk. The main board and the disk receiving/ejecting mechanism are placed between the main frame and the cover and are coupled to the main frame.

BACKGROUND OF THE INVENTION

This invention relates to a thin-profile disk drive for use in recordingand reproducing information to and from a flexible disk (FD) as amagnetic recording medium.

As well known, a flexible disk drive (FDD) is for recording andreproducing information to and from a flexible magnetic disk as amagnetic recording medium. The magnetic disk is contained in a plasticcase. A combination of the magnetic disk and the plastic case isgenerally called a disk cartridge.

Such a disk drive comprises a main frame and a cover attached oppositeto the main frame. In order to recording or reproducing the information,the disk cartridge is set or inserted between the main frame and thecover and held on a disk table provided in the disk drive. The disktable has a rotation shaft in the manner such that the center of themagnetic disk is coincident with the rotation shaft of the disk table.

The disk table is supported on a main frame is driven and rotated by aspindle motor which is mounted on a motor frame. The spindle motor isfor rotating the magnetic disk included in the disk cartridge. The diskdrive further comprises a pair of magnetic heads, i.e., upper and lowermagnetic heads, for reading/writing data to/from the magnetic disk inthe disk cartridge. The upper magnetic head is supported by a headassembly at its end. The head assembly is located on a rear side of thedisk drive and comprises upper and lower head supporting memberssupporting the upper and the lower magnetic heads, respectively. Thehead assembly is disposed above a principal surface of the main frameand spaced from the main frame. The head assembly supports the uppermagnetic head at its end so that the upper magnetic head is movable in apredetermined radial direction with respect to the magnetic disk.

The disk drive is often subjected to an external stress applied betweenthe main frame and the cover. For example, when the disk drive isstrongly held by a user's hand before the disk cartridge is insertedtherein, at least one of the main frame and the cover is bent. As aresult, it is assumed that the disk drive is deformed. The deformationof the disk drive or other components due to the external stress causesa displacement of the head assembly. When the disk cartridge is insertedinto the disk drive in this condition, the magnetic heads may be damagedby the disk cartridge.

SUMMARY OF THE INVENTION

It is therefore an object of this invention to provide a disk drivecapable of preventing a magnetic head from being damaged even uponoccurrence of deformation of the disk drive.

Other objects of the present invention will become clear as thedescription proceeds.

According to this invention, there is provided a disk drive for using adisk cartridge including a magnetic disk, the disk drive comprising amain frame, a cover opposite to the main frame, a main board placedbetween the main frame and the cover and fixed to the main frame, a diskreceiving/ejecting mechanism placed between the main frame and the coverand coupled to the main frame for receiving and ejecting the diskcartridge, a head assembly placed between the main frame and the coverand movable in a radial direction of the magnetic disk, and areinforcing arrangement coupled to the main frame, the main board, andthe disk receiving/ejecting mechanism for resisting an external stress,applied between the main frame and the cover, to protect the headassembly.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a plan view of an existing disk drive;

FIG. 2 is a plan view of the disk drive illustrated in FIG. 1 when adisk cartridge is being inserted;

FIG. 3 is a plan view of the disk drive illustrated in FIG. 1 when thedisk cartridge is completely inserted;

FIG. 4 is a plan view showing a disk holder assembly used in the diskdrive illustrated in FIG. 1;

FIGS. 5A, 5B, and 5C are a plan view, a right side view, and a rear viewof an eject lever used in the disk drive illustrated in FIG. 1;

FIG. 6 is a plan view of a disk drive according to an embodiment of thisinvention in the state where a cover is removed;

FIG. 7 is an exploded perspective view of the disk drive illustrated inFIG. 6;

FIG. 8 is a plan view of a characteristic part of the disk driveillustrated in FIG. 6; and

FIG. 9 is an exploded perspective view of the characteristic part of thedisk drive illustrated in FIG. 8.

DESCRIPTION OF THE PREFERRED EMBODIMENT

In order to facilitate an understanding of this invention, an existingflexible disk drive (FDD) will at first be described with reference tothe drawing.

Referring to FIGS. 1 through 3, the existing flexible disk drive of a3.5-inch type is adapted to drive a flexible magnetic disk of a 3.5-inchtype. In FIG. 1, a disk cartridge 140 illustrated in FIG. 2 is notinserted. In FIG. 2, the disk cartridge 140 is being inserted. In FIG.3, the disk cartridge 140 is completely inserted. In each of FIGS. 1through 3, an upper cover (not shown) is removed.

The disk cartridge 140 contains a flexible magnetic disk as a magneticrecording medium. The disk cartridge 140 is inserted into the disk drivein an inserting direction depicted by an arrow A in FIGS. 1 through 3.The disk cartridge 140 inserted into the disk drive is held on a disktable 111 in the manner such that the center of the magnetic disk iscoincident with a rotation shaft 111 a of the disk table 111. The disktable 111 is rotatably supported on an upper surface of a motor frame(not shown) attached to a main frame 113. The rotation shaft 111 a hasan axial direction (perpendicular to a drawing sheet) parallel to athickness direction of the main frame 113.

The disk table 111 is driven and rotated by a spindle motor 135 disposedon the motor frame so that the magnetic disk in the disk cartridge 140is rotated. A main board 130 with a number of electronic componentsmounted thereon is attached to the main frame 113 and the motor frame.

The disk drive comprises a pair of magnetic heads, i.e., upper and lowermagnetic heads for reading/writing data to/from the magnetic disk in thedisk cartridge 140. In the figures, only the upper magnetic head 114 isillustrated.

The upper magnetic head 114 is supported by a head assembly 115 at itsend. The head assembly 115 is located on a rear side of the disk drive.The head assembly 115 comprises an upper head supporting member 115 asupporting the upper magnetic head 114 and a lower head supportingmember (not shown) supporting the lower magnetic head.

The head assembly 115 is disposed above a principal surface of the mainframe 113 and spaced from the main frame 113, as will later bedescribed. The head assembly 115 supports the upper magnetic head 114 atits end so that the upper magnetic head 114 is movable in apredetermined radial direction (depicted by an arrow B in FIGS. 1through 3) with respect to the magnetic disk.

The main frame 113 has a rear wall 131 with a stepping motor 116 fixedthereto. The stepping motor 116 serves to linearly drive the headassembly 115 in the predetermined radial direction B. More in detail,the stepping motor 116 has a rotation shaft (driving shaft) 161extending in parallel to the predetermined radial direction B. Therotation shaft 161 is provided with a male thread or external thread.The rotation shaft 161 has a forward end inserted through a hole formedin a support member 131 attached to the principal surface of the mainframe 113. The rotation shaft 161 is limited in position to extend inparallel to the predetermined radial direction B and the forward end ofthe rotation shaft 161 is rotatably held.

On the other hand, the head assembly 115 has an arm 151 extending fromthe lower head supporting member to the rotation shaft 161. The arm 151has a forward end engaged with a root of the male thread formed on anouter peripheral surface of the rotation shaft 161. Therefore, when therotation shaft 161 is rotated, the forward end of the arm 151 is movedalong the root of the male thread of the rotation shaft 161 so that thehead assembly 115 itself is moved in the predetermined radial directionB. Thus, the stepping motor 116 serves as a driving arrangement forlinearly moving the head assembly 115 in the predetermined radialdirection B.

The rotation shaft 161 is disposed on one side of the head assembly 115.Therefore, the one side of the head assembly 115 is movably supported bythe rotation shaft 161 and spaced from the principal surface of the mainframe 113.

However, by the rotation shaft 161 alone, it is impossible to support awhole of the head assembly 115 with a space kept from the principalsurface of the main frame 113. Therefore, the head assembly 115 issupported and guided by a guide bar (not shown) on the other side of thehead assembly 115.

Specifically, the guide bar is arranged on the other side of the headassembly 115 opposite to the rotation shaft 161. The guide bar extendsin parallel to the predetermined radial direction B and has one end andthe other end fixed to the principal surface of the main frame 113 aswill later be described. The guide bar serves to guide the head assembly115 in the predetermined radial direction B. Thus, the head assembly 115as a whole is supported with a space kept from the principal surface ofthe main frame 113.

A flexible printed circuit (FPC) (not shown) extends from the headassembly 115 towards the guide bar. The FPC is electrically connected tothe main board 130 attached to the principal surface of the main frame113.

The lower head supporting member of the head assembly 115 also serves asa supporting frame supporting the head assembly 115 so that the headassembly 115 is slidable along the guide bar. The lower head supportingmember has a protruding portion (not shown) protruding towards the guidebar. The guide bar is slidably fitted into the protruding portion.

The disk drive further comprises an elect plate 121 and a disk holder122. Each of the main frame 113, the elect plate 121, and the diskholder 122 is formed by punching, pressing, and bending a metal plate.

The elect plate 121 is mounted on the main frame 113 to be slidable inthe inserting direction A and an ejecting direction opposite thereto,i.e., to be slidable in a back-and-forth direction.

The disk holder 122 is disposed under the elect plate 121. Asillustrated in FIG. 4, the disk holder 122 has a principal surface 220and a pair of side walls 221 formed on opposite sides of the principalsurface 220 and faced to each other. The side walls 221 have a pair ofpins 222 and 223, respectively.

The disk holder 122 has a generally rectangular opening 224 formed in acenter area inward in the inserting direction A. Specifically, theopening 224 is formed at a position corresponding to the upper headsupporting member 115 a and extends in the predetermined radialdirection B. The opening 224 is surrounded by a generally U-shaped ridge225 rising upward from the principal surface 220.

On the other hand, the head assembly 115 comprises a pair of side arms153 (see FIGS. 1 through 3) extending in a lateral direction. The sidearms 153 are located on or above the ridge 225. In the state where thedisk cartridge 140 is ejected from the disk holder 122, the side arms153 are engaged with the ridge 225 so that the upper magnetic head 114and the lower magnetic head are separated from each other. Furthermore,the disk holder 122 has another opening 226 formed at a right-hand sideof the opening 224 inward in the insertion direction A. The opening 226has a shape such that the rotation of a lever part of an eject lever(which will later be described) 125 is allowed.

The principal surface of the main frame 113 is covered with a sub frame123. The sub frame 123 has four corners fixed to the main frame 113 byscrews 231. Between the sub frame 123 and the eject plate 121, ejectsprings 124 are bridged. On the main frame 113, the eject lever 125 isrotatably arranged in the vicinity of the head assembly 115.

Referring to FIGS. 5A through 5C, the eject lever 125 will be described.The main frame 113 is provided with a rod pin (not shown) standing fromthe principal surface thereof and extending upward from a predeterminedposition on the right side and the rear side. The eject lever 125comprises a cylindrical part 250 to receive the rod pin fitted thereto,an arm part (lever part) 251 extending from the cylindrical part 250 ina radial direction, a protruding part 252 formed on the arm part 251 andextending upward, and an arc-shaped locking part 253 extending from afree end of the arm part 251 in a circumferential direction.

The eject lever 125 is provided with an eject lever spring (not shown)attached around the cylindrical part 250. The eject lever spring urgesthe eject lever 125 in a counterclockwise direction in the figure.

The protruding part 252 is engaged with a forward end of the diskcartridge 140 to control a sliding movement of the eject plate 121 inthe back-and-forth direction.

The eject lever 125 has a tongue part 254 extending in parallel to thearm part 251 towards the spindle motor 116. The tongue part 254 has aforward end 254 a expanding upward. The forward end 254 a serves toprevent the disk cartridge 140 from colliding with the lower magnetichead when the disk cartridge 140 is inserted into the disk drive.

The protruding part 252 has a protrusion 252 a protruding further upwardto be engaged with a hook portion 261 a of a disk shutter arm 126 whichwill later be described.

The eject lever 125 further has a stopper part 255. The stopper part 255is adapted to be engaged with the disk shutter arm 126 (which will laterbe described) to prevent the disk shutter arm 126 from returning to itsinitial position when the disk cartridge 140 is completely received inthe disk drive.

On a right upper corner of the disk holder 122, the disk shutter arm 126is attached to be rotatable around an arm pin 260. The disk shutter arm126 has an arm part (lever part) 261 extending from the right uppercorner in the radial direction, and an arm bushing 262 formed at an endof the arm part 261 and extending downward.

The arm part 261 has the hook portion 261 a engaged with the protrusion252 a. As illustrated in FIG. 4, the arm bushing 262 is loosely fittedto the opening 226.

The arm bushing 262 has an end portion 262 a. The end portion 262 a isengaged with a right upper edge of a shutter of the disk cartridge 140to controllably open and close the shutter. The arm bushing 262 furtherhas a protruding portion 262 b. The protruding portion 262 is engagedwith the stopper part 255 when the disk cartridge 140 is completelyreceived in the disk drive.

The disk shutter arm 126 is urged by a shutter arm spring 263 in thecounterclockwise direction.

Specifically, the shutter arm spring 263 is bridged between the arm part261 and the disk holder 22. To the ridge 225, an upper magnetic headguard 132 is attached to protect the upper magnetic head 114 so that thedisk cartridge 140 does not collide with the upper magnetic head 114when it is inserted into the disk drive.

The disk holder 122 is provided with a reverse insertion preventingspring (not shown) attached to the right side of the principal surface220 thereof. A combination of the disk holder 122, the disk shutter arm126, the arm pin 260, the upper magnetic head guard 132, the reverseinsertion preventing spring, and the disk shutter arm 126 forms a diskholder assembly.

The main frame 113 has a front end portion provided with a front panel127 attached thereto. The front panel 127 has an opening (not shown)allowing passage of the disk cartridge 140 and a door (not shown) forclosing the opening. The front panel 127 is provided with an ejectbutton 128 protruding therefrom to be movable backward and forward. Theeject button 128 is fitted to a protruding part (not shown) formed at afront end of the elect plate 121 to protrude forward.

With the above-mentioned structure, the hook portion 261 a is engagedwith the protrusion 252 a as illustrated in FIG. 1 to limit the rotationof the eject lever 125 when the disk cartridge 140 is not inserted intothe disk drive. Thus, the eject lever 125 is prevented from beingrotated over a predetermined rotation angle unless the disk cartridge140 is inserted into the disk drive.

Next, description will be made of an operation of inserting the diskcartridge 140 into the disk cartridge and an operation of ejecting thedisk cartridge 140 inserted in the disk drive.

Before the disk cartridge 140 is inserted into the disk drive, the ejectlever 125 and the disk shutter arm 126 are located at positionsillustrated in FIGS. 1 and 5. Specifically, the protrusion 252 a isengaged with the hook portion 261 a. In this state, a stopper part 255of the eject plate 121 is engaged with the locking part 253.

In this state, the pins 222 and 223 are located at upper positions inside walls 221 is located at an elevated position such that the diskcartridge 140 is acceptable. In this state, the side arms 153 areengaged with the ridge 225 and the upper magnetic head 114 is located atan upper position and separated from the lower magnetic head.

In this state, a user holds the disk cartridge 140 with its forward endin contact with the door of the front panel 127 and inserts the diskcartridge 140 in a normal state into the disk drive in the insertingdirection A, as illustrated in FIG. 2. Then, as illustrated in FIG. 2,the shutter of the disk cartridge 140 is engaged with the end portion262 a. After this time instant (this position), the disk cartridge 140is further pushed inward against the urging force of the shutter armspring 263 attached to the disk shutter arm 126. Then, the arm bushing262 rotates in the opening 226 in the clockwise direction depicted by anarrow D in FIG. 4. Following the rotation of the arm bushing 262, theshutter of the disk cartridge 140 slides against the urging force of theshutter arm spring 263. As a consequence, the opening 226 is graduallyexposed.

Immediately before the shutter of the disk cartridge 140 is sufficientlyopened by the disk shutter arm 126 and the disk cartridge 140 iscompletely received in the disk drive, the forward end of the diskcartridge 140 is engaged with the protruding part 252. At this time, theprotrusion 252 a is disengaged from the hook portion 261 a. Therefore,the eject lever 125 is rotatable in the clockwise direction.

When the disk cartridge is further pushed inward in the disk drive, theeject lever 125 is rotated against the eject lever spring attachedthereto. As a consequence, the locking part 253 is disengaged from thestopper part 212. Therefore, the eject plate 121 is slightly slidesforward (reverse to the inserting direction A). This is because theeject plate 121 is urged forward by the eject spring 124.

On the other hand, the disk holder 122 is moved downward by the forwardmovement of the eject plate 121. This is because the pins 222 and 223formed on the side walls 221 are inserted into the cam portions formedon side walls of the eject plate 121.

In the above-mentioned manner, the side arms 153 are disengaged from theridge 225 and the upper head supporting member 115 a is moved downward.As a consequence, the magnetic disk in the disk cartridge 140 is clampedby the upper magnetic head 114 formed at the end of the head assembly115 and the lower magnetic head. At this time, the protruding portion262 b is engaged with the stopper part 255 so that the disk shutter arm126 is prevented from returning to its initial position. Since the ejectplate 121 slightly slides forward, the eject button 128 slightlyprotrudes forward from the front panel 127. This state is illustrated inFIG. 3. Thereafter, data can be read and written from and to themagnetic disk in the disk cartridge 140 by at least one of the uppermagnetic head 114 and the lower magnetic head. Next, description will bemade of the operation of ejecting the disk cartridge 140 received in thedisk drive. In this case, the user presses the eject button 128 rearwardin the inserting direction A. As a consequence, the eject plate 121slides on the main frame 113 rearward in the inserting direction A.Simultaneously, the pins 222 and 223 move along the cam portions of theeject plate 121 so that the disk holder 122 is elevated. As aconsequence, the side arms 153 are engaged with the ridge 225. The uppermagnetic head 114 supported at the end of the head assembly 115 and thelower magnetic head are separated from the magnetic disk in the diskcartridge 140. When the eject button 128 is further pushed rearward inthe inserting direction A, the disk holder 122 is located at apredetermined upper position and the eject lever 125 is rotated in thecounterclockwise direction due to the urging force of the eject leverspring.

Simultaneously, the stopper part 255 is disengaged from the protrudingportion 262 b. Due to the urging force of the shutter arm spring 263,the disk shutter arm 126 is rotated in the counterclockwise directionreverse to the direction depicted by the arrow D in FIG. 4. As aconsequence, the disk cartridge 140 received in the disk holder 122 ispushed out in the ejecting direction opposite to the inserting directionA so that the disk cartridge 140 is ejected from the disk drive. In thisstate, the locking part 253 is engaged with the stopper part 212 so thatthe eject plate 121 is prevented from moving towards the front panel127.

A cover (not shown) is attached to the main frame 113 and assembling iscompleted. The disk drive is often subjected to an external stress. Forexample, when the disk drive is held by a user's hand before the diskcartridge 140 is inserted therein, the cover is pressed and bent so thatthe disk drive is deformed.

However, those components other than the disk holder 122 is subjected tothe external stress to be deformed. Therefore, the deformation of thecomponents due to the external stress is finally transmitted to the diskholder 122. In this event, when the disk cartridge 140 is inserted intothe disk drive, the upper magnetic head 114 may be damaged.

Specifically, the upper magnetic head 114 lifted up by the disk holder122 may be bent under the external stress to be drooped. In this state,the upper magnetic head 114 collides with the lower magnetic head.Therefore, the upper magnetic head 114 is damaged by mechanical shock.

Now, description will be made of an embodiment of this invention.Similar parts will not be described in detail.

Referring to FIGS. 6 and 7, a disk drive 1 according to the embodimentof this invention comprises a main frame 11 provided with a main board 5and a spindle motor 10.

Herein, a lower side in FIG. 6 is assumed to be a front side. The mainframe 11 has a flat base plate 11 a, a pair of side plates 11 b and 11 cformed on opposite sides of the base plate 11 a to extend from the frontside to a rear side and standing up to be substantially perpendicular tothe base plate 11 a, and a rear plate 11 d formed at a rear end of thebase plate 11 a and standing up to be substantially perpendicular to thebase plate 11 a.

The main frame 11 is provided with a front bezel 16 formed at its frontend. The front bezel 16 is rotatable around an upper end thereof betweena closed position and an opened position and is urged by a spring 16 ato the closed position. The base plate 11 a is provided with a diskreceiving/ejecting mechanism 20, a head assembly 30 movable forward andrearward, and a stepping motor 40 for moving and positioning the headassembly 30.

The disk receiving/ejecting mechanism 20 comprises an eject plate 21 anda disk holder 22 disposed inside the eject plate 21. A disk cartridge(see FIG. 2) containing a flexible magnetic disk is received in a spacebetween the disk holder 22 and the base plate 11 a and on a turn table13.

The eject plate 21 and the disk holder 22 are stacked to each other. Theeject plate 21 is urged frontward (downward in FIG. 6) by a pair of coilsprings 23 formed on opposite sides with respect to the disk holder 22.The disk holder 22 is provided with an eject lever 25 formed on one endface (right upper side in FIG. 6) thereof to be rotatable around a shaft25 a. Between the eject lever 25 and the disk holder 22, a coil spring24 (corresponding to the shutter arm spring 263 in FIG. 2) is bridged.

When the disk cartridge is received, one end of the disk cartridge isbrought into contact with one end of the eject lever 25 to rotate theeject lever 25 around the shaft 25 a in a clockwise direction. At apredetermined position, the eject lever 25 is engaged with the diskholder 22 to be stopped.

On the other hand, when the disk cartridge is ejected, an eject button21 a is pushed rearward (upward in FIG. 6). Then, the eject lever 25 isdisengaged from the disk holder 22 so that the eject lever 25 is rotatedin a counterclockwise direction by a restoring force of the coil spring24 to push out the disk cartridge.

As seen from FIG. 7, the disk drive 1 comprises a main portion 50, adisk receiving/ejecting mechanism 20 received in the main portion 50,and a cover 61 covering an upper side of the disk drive 1.

Referring to FIGS. 8 and 9, the main portion 50 comprises the main frame11, the spindle motor 10 mounted on the base plate 11 a, and the mainboard 5 mounted on the base plate 11 a in an area around the spindlemotor 10.

The main board 5 has a generally L shape. The main board 5 is connectedto a flexible board 52 through a solder connecting portion 53. The mainboard 5 is provided with a plurality of electronic components 5 bconnected through a circuit pattern (not shown). The main board 5 isprovided with a connector 5 c mounted on its one end to carry outelectric connection with an external circuit. Screw holes 6′ is formedto fix the main board 5 to the base plate 11 a.

The base plate 11 a is provided with a head assembly 30 mounted on itsone end. The head assembly 30 has one side inserted into a guide rail 18and the other side engaged with an outer peripheral groove of a drivingrod (screw rod) 41 a connected to a motor body 41 of the stepping motor40.

On the rear side of the head assembly 30, a board 38 for electricalconnection is fastened to the main frame 11 by a screw 38 a. Thestepping motor 40 is disposed on one side of the head assembly 30. Thestepping motor 40 is positioned and fixed by fixing a support member 43via a screw 44.

On one side of the stepping motor 40, a small-sized circuit board 42 isdisposed to supply an electric current. The guide rail 18 is fixed by afixing metal 17 to the base plate 11 a together with the main board 5.

On the upper surface of the base plate 11 a, a lifting lever 46 forlifting the disk cartridge in cooperation with the eject plate 21, theeject lever 25, and an unlock lever 47 for disengaging the disk holder22 from the eject plate 21 are arranged.

Referring to FIG. 9, the main portion 50 is assembled in the followingmanner. The main board 5 is fixed by screws 6 to the base plate 11 a.The fixing metal 17 is attached by a screw 17 a to hold an inside of arear end of the main board 5. The fixing metal 17 also serves to fix theguide rail 18.

Next, the flexible board 52 with a solenoid coil 55 is attached to thebase plate 11 a so that the center of the flexible board 52 iscoincident with a through hole 12 provided with a bearing 12 a. Abearing 14 is put on the center of the flexible board 52. A rotationshaft 13 a of the turn table 13 is rotatably inserted into the throughhole 12 through the bearing 12 a. The turn table 13 is attached so thatgrooves 13 b of the turn table 13 are coincident with cut-and-raisedportions 19 formed on the base plate 11 a. The turn table 13 isrotatable once it is attached. Unless the grooves 13 b are matched incircumferential position with the cut-and-raised portions 19, the turntable 13 is inhibited from being released upward.

As seen in a vertical section, the head assembly 30 has a generally Ushape and comprises an upper head supporting member 31 and a lower headsupporting member 34 faced to the upper head supporting member 31 (seeFIG. 9). An upper magnetic head (magnetic head element) 33 is arrangedinside the upper head supporting member 31. A lower magnetic head(magnetic head element) is arranged inside the lower head supportingmember 34, although not shown in the figure.

On one side of the head assembly 30, the stepping motor 40 is disposed.The stepping motor 40 has the driving rod 41 a protruding from its oneend. The driving rod 41 a has an outer peripheral groove 41 b engagedwith one end of an arm 35 of the head assembly 30. The stepping motor 40is held by fixing the support member 43 by the screw 44 to a protrudingportion 45 of the base plate 11 a.

On the main board 5 exposed on the left side of the head assembly 30, astanding member 48 made of a plastic material and having a S shape asseen in a plan view is formed. The standing member 48 serves as a guidefor a signaling flexible cable connected to the head assembly 30. Asupporting part 43 a of the support member 43 and the standing member 48are substantially equal in height and stand up towards the cover 61.

The disk holder 22 has a generally rectangular opening 22 a formed in acenter area inward in an inserting direction A along which the diskcartridge is inserted. Specifically, the opening 22 a is formed at aposition corresponding to the upper head supporting member 31 andextends in a predetermined radial direction B. The opening 22 a issurrounded by a generally U-shaped ridge 22 b rising upward from theprincipal surface of the disk holder 22.

The disk holder 22 is provided with a cut-and-raised part 22 f formedfrontward from the opening 22 a and rising from the principal surface ofthe disk holder 22.

Each of the standing member 48, the supporting part 43 a, and thecut-and-raised part 22 f serves to maintain mechanical strength againstcompression in the vertical direction and serves as a reinforcing partresisting against deformation of the disk drive 1.

The supporting part 43 a is located rearward in the inserting directionA and opposite to one side of the head assembly 30. The standing member48 is located rearward in the inserting direction A and opposite to theother side of the head assembly 30.

On the other hand, the upper head supporting member 31 comprises a pairof side arms 31 a extending in a lateral direction and a pair of upperarms 31 b connected to the side arms 31 a, respectively. The side arms31 a are located on or above the ridge 22 b.

In the state where the disk cartridge is ejected from the disk holder22, the side arms 31 a are engaged with the ridge 22 b so that the uppermagnetic head 33 and the lower magnetic head are separated from eachother. Furthermore, the disk holder 22 has another opening 22 c formedat a right-hand side of the opening 22 a inward in the insertingdirection A. The opening 22 a has a shape such that the rotation of alever part of the eject lever 25.

The lifting lever 46 for lifting the disk cartridge in cooperation withthe eject plate 21 upon ejecting the disk cartridge is rotatablyattached to the base plate 11 a by a pin 46 a. The unlock lever 47 forreleasing the engagement between the disk holder and the eject plate 21in the back-and-forth direction is rotatably attached to the base plate11 a by a pin 47 a. The main portion 50 illustrated in FIG. 8 isassembled in the manner illustrated in FIG. 9.

Furthermore, the disk receiving/ejecting mechanism 20 is received in themain portion 50 as illustrated in FIG. 7. Then, the structureillustrated in FIG. 6 is obtained. Furthermore, the cover 61 illustratedin FIG. 7 is attached and assembling of the disk drive 1 is completed.

The disk drive 1 thus completed may be subjected to an external stress.For example, when the disk drive 1 is held by a user's hand before thedisk cartridge is inserted therein, the cover 61 is pressed and bent sothat the disk drive 1 is deformed.

In this event, a combination of the standing member 48, the supportingpart 43 a, and the cut-and-raised part 22 f serves as a reinforcingarrangement which is for resisting the deformation of the disk drive 1to protect the head assembly 30. it is to be noted that the standingmember 48, the supporting part 43 a, and the cut-and-raised part 22 fare placed at three corners of a triangle shape, respectively. When thedeformation of the components due to the external stress is finallytransmitted to the disk holder 22, the cut-and-raised part 22 f liftingthe upper magnetic head 33 serves to correct the deformation.

Specifically, the upper magnetic head 33 and the disk holder 22 aresimultaneously deformed by the same amount when subjected to theexternal stress. Therefore, the upper magnetic head 33 located in theopening 22 a does not project beyond the ridge 22 b so that the uppermagnetic head 33 is not damaged or broken.

As described above, the disk holder 22 lifting the upper magnetic head33 is provided with the cut-and-raised part 22 f as a countermeasureagainst the external stress. In the normal condition, the upper magnetichead 33 is accommodated in the opening 22 a. The upper magnetic head 33and the disk holder 22 are simultaneously deformed by the same amountwhen subjected to the external stress. Therefore, the upper magnetichead 33 located inside the ridge 22 b does not project beyond the ridge22 b so that the upper magnetic head 33 is prevented from being damaged.

1. A disk drive for a disk cartridge which includes a magnetic disk,said disk drive comprising: a main frame; a cover opposite to said mainframe; a main board placed between said main frame and said cover andfixed to said main frame; a disk receiving/ejecting mechanism placedbetween said main frame and said cover and coupled to said main framefor receiving and electing said disk cartridge; a head assembly placedbetween said main frame and said cover and movable in a radial directionof said magnetic disk; and a reinforcing system coupled to said mainframe, said main board, and said disk receiving/ejecting mechanism forresisting an external stress applied between said main frame and saidcover so as to protect said head assembly; wherein said diskreceiving/ejecting mechanism comprises: an eject plate coupled to saidmain frame for ejecting said disk cartridge; and a disk holder coupledto said eject plate for holding said disk cartridge, and wherein saidreinforcing system comprises: a supporting part connected to said mainframe and standing up towards said cover; a standing member connected tosaid main board and standing up towards said cover; and a cut-and-raisedpart formed on said disk holder and standing up towards said cover.
 2. Adisk drive according to claim 1, wherein said supporting part, saidstanding member, and said cut-and-raised part are respectively placed atthree corners of a triangle shape.
 3. A disk drive according to claim 1,wherein said supporting part is located rearward in an insertingdirection of said disk cartridge and faced to one side of said headassembly, wherein said standing member is located rearward in theinserting direction and faced to the other side of said head assembly,and wherein said cut-and-raised part is located frontward in theinserting direction.
 4. A disk drive according to claim 1, furthercomprising a support member connected to said main frame, saidsupporting part being formed on said support member.
 5. A disk driveaccording to claim 4, further comprising a stepping motor supported bysaid support member for moving said head assembly in the radialdirection, said supporting part supporting a rotation shaft of saidstepping motor.